function b = readS(iStream)
 
 disp 'Reply:'
 
 % Number of messages
 n = iStream.available;
 
 % Buffer size = 500 characters
 b = zeros(1,500);
 for i = 1:n
     b(i) = iStream.read();
 end
 
 if (b(1) ~= 0)
     disp (char(b))
 end
 disp ('')